Last month, Portland adventurer Colin O'Brady and a crew of five others became the first to cross the Drake Passage—one of the most treacherous waterways in the world—with no mechanical assistance.

The 600-mile trip off the southern tip of South America took the crew 13 days to complete, Time reported. The crew had to row non-stop in order to keep from capsizing, so throughout the trek, three rowed for 90 minutes while the other three rested.

"It was quite harrowing," O'Brady told The Associated Press. "By the end, we all lost a good amount of weight and were delirious from the sleep deprivation."

The other men in the Drake Passage crew included Jamie Douglas-Hamilton of Scotland, Fiann Paul of Iceland, Cameron Bellamy of South Africa, Andrew Towne of North Dakota and John Petersen of California.

Douglas-Hamilton told Time that at one point during the crossing, a strap used to anchor his ankles while rowing cut through his boots and skin all the way down to his bone.

Discovery followed O'Brady and the others throughout the expedition and footage of the passage can be viewed here.